Santiago Javier Nenda

Introduction of the American Bullfrog Lithobates catesbeianus (Anura: Ranidae) in Natural and Modified Environments: An Increasing Conservation Problem in Argentina

ABSTRACT. Several previous studies have established that the introduction of the American bullfrog, Lithobates catesbeianus, produces negative effects on native communities. Herein, the American bullfrog is reported for the first time in the province of Buenos Aires, Argentina in the locality of 9 de Julio. The stomach contents of the collected specimens were examined and the reproduction of the species was also confirmed at the study area. A total of 85.7% (n = 30) of the analyzed stomachs contained prey items, and eleven of these were identified. The prey items belonged mostly to coleopterans (50%) and vertebrates (11%). The pathogen Batrachochytrium dendrobatidis was not found on skin samples examined. The installation of Lithobates catesbeianus breeding facilities contributes to the incidental release of this species. A tightening of rules in the regulation of aquaculture activities and the use of control programs for naturalized populations are necessary to address the increasing dispersion of the species in Argentina and potential ecological problems.

Discovery of two new species of Phymaturus (Iguania:Liolaemidae) from Patagonia, Argentina, and occurrence of melanism in the patagonicus group

Comprehensive studies recently published on the evolution and systematics of Phymaturus (morphological and molecular ones, respectively) revealed not only a historical pattern and subclades within the traditional palluma and patagonicus groups but also a still not fully understood unsuspected diversity. Several populations in northern and southern Argentina may represent independent lineages that deserve formal description. Two of these populations were studied in the present contribution and are easily distinguished from all the other species in the genus. One of these populations is from Rio Negro province and belongs to the patagonicus group; it exhibits a particular dorsal colouration pattern and several individuals are melanic, a characteristic never reported before for the genus, with the exception of P. tenebrosus . A careful examination of melanic individuals revealed the same dorsal pattern as that of non-melanic ones, although it is hidden. We also report the discovery of melanic individuals of two other species that are probably closely related: P. ceii and P. sitesi . The melanism found in the patagonicus group differs from the head melanism of males in certain species of the palluma group because in the former group melanism is not ruled by sexual dimorphism and involves the whole animal. The other population studied in this contribution belongs to the palluma group and is described as a new species because its colour pattern and scalation differ from those of all the other members of the palluma group. Finally, we discuss the position of these new lizard species in the context of the available phylogenetic hypothesis and the occurrence and evolution of melanism in the patagonicus group.

Distribution and natural history notes on Tachymenis chilensis chilensis (Schlegel, 1837) (Reptilia: Serpentes: Dipsadidae) in Argentina

We revisit the distribution and natural history data of Tachymenis chilensis chilensis (Schlegel, 1837) in Argentina based on compiled and novel records, extending its northern and southern distribution from the previously known localities in Argentina. We recorded two prey items in Argentinean populations: Rhinella rubropunctata , reported for the first time, and Liolaemus pictus . Tachymenis c. chilensis is mainly found in forested habitats, generally near wetlands with abundant populations of amphibians. The latitudinal range occupied by T. c. chilensis in Argentina is similar to that in Chile, but its northern distribution limit reaches the lowest latitudes in Chile. This is probably due to the higher humidity levels in the western slopes of the Andes and the barrier effect of the highest mountain ranges in this area.

Amphibia, Anura, Microhylidae, Elachistocleis skotogaster : map of geographic distribution, distribution extension, and new altitudinal records

The genus Elachistocleis is a neotropical group of small sized microhylid frogs, which is represented by two species in Argentina: Elachistocleis bicolor (Guerin-Meneville, 1838) and E. skotogaster Lavilla, Vaira and Ferrari, 2003. E. skotogaster was only known for the type locality Los Toldos, Santa Victoria department, Salta, 1100 m (Lavilla et al. 2003; Lavilla 2004), however, specimens from Bolivia with spotted bellies that are currently attributed to Elachistocleis ovalis might pertain to E. skotogaster (Lavilla 2004).

Occurrence of Tachymenis chilensis chilensis (Schlegel, 1837) (Reptilia: Serpentes: Dipsadidae) and other herpetological fauna from Epu Lauquen Natural Protected Area, Neuquén, Argentina

We report a new specimen of Tachymenis chilensis chilensis from Epu Lauquen Natural Reserve, Neuquen, Argentina. This specimen represents the northernmost voucher of T. c. chilensis in Argentina and confirms the presence of the subspecies occupying moist habitats remnants in dry areas of northern Neuquen province. Moreover, this record corresponds to the northernmost population of T. c. chilensis in a protected area in Argentina. We also found two sympatric anurans, Rhinella spinulosa and Pleurodema thaul . Both anurans also represent the first record of amphibians at Epu Lauquen Natural Reserve.